Skiving tool holding means for automatic screw machines



Jan. 13, 1953 J. R. SMITH 2,625,068

SKIVING TOOL HOLDING MEANS FOR AUTOMATiC SCREW MACHINES Filed Feb. 10, 1951 INVENTOR. F164. JOHN R S /TH,

Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE SKEVING TOOL HOLDING MEAN S FOR AUTOMATIC SCREW MACHINES 3 Claims.

This invention relates to a certain new and useful improvement in tool holding devices, designed primarily for use in connection with automatic screw machines of the type well known in the art as Brown and Sharpe automatic screw machines, although obviously not restricted to a specific screw machine, as the device is of such a construction as will permit it to readily adapt itself to similar machines having the same characteristics.

The invention contemplates a readily detachable holder for the detachable mounting support of a skiving cutter tool, in a manner to greatly facilitate the accurate adjustment of the tool with respect to the work stock and permits the quick and easy removal of the tool for purposes of resharpening and subsequent replacing upon the holder without disturbing the already accurate adjustment of the holder.

The device of the present invention is adaptable through an adjustable pivotal mounting upon the conventional tool posts of the automatic screw machines and its pivotal mounting is such as to permit its use upon the tool posts of either the forward or rear slides of the machine and is highly efficient in either direction of spindle rotation and will eifect an accurate skiving operation over or under the work. On the well known Brown 8: Sharpe automatic screw machines, adjustment of the holder is easily and accurately accomplished to a fine degree by the conventional eccentric bushing of the tool post after first loosening the clamping hook bolt.

A further and important object of the invention resides in the extreme simplicity of the tool holder and its ability to rigidly and detachably support a skiving tool in a manner that permits of quick and easy assembly of the tool with the holder through the medium of a single clamping device that maintains the tool in absolutely accurate alignment. with the holder under all conditions of use and provides a holder for skiving tools that permits of its use in places difficult, if not impossible, with skiving tool holders previously employed.

Other distinct and novel features of construction and operation will be readily apparent during the course of the following description, reference'being had to the accom ying drawings wherein has been illustrated a ment of the device and wherein like characters of reference are employed to denote like parts throughout the several figures.

In the drawing:

Figure 1 is a side elevation of a conventional ferred embodi- 2 tool post and associated slide, showing the im proved tool holder and tool supported thereon in operative relation to the work,

Figure 2 is a front elevation of the tool holder and skiving tool, removed from the tool post,

Figure 3 is a top plan view of the assembled tool holder and tool as supported upon the tool post,

Figure 4 is a vertical longitudinal section through the tool holder and associated skiving tool, taken on line 44 of Figure 2,

Figure 5 is a perspective view of the improved tool holder with the tool omitted, for sake of clearness, and

Figure 6 is a perspective view of the skiving tool.

Referring specifically to the drawings, and particularly to Figures 1 and 3, the numeral 5 designates the front cross slide of the conventional Brown & Sharpe automatic screw machine, supporting the Well known tool post 6. The tool post 5 is clamped to the slide in the usual manner by the clamping bolt '1. The tool post 6 is provided with the usual wing extension 8, upon which is mounted the tool holder of the present invention, designated as a whole, by the numeral 9. A conventional hook bolt I0, shiftable axially through an eccentric bushing l I, indicated in dotted lines in Figure 3, serves to clamp the tool holder 9 rigidly against the tilt plate 12. The bolt I0 is urged in axial movement by the nut l3, while a hex head l4 serves to actuate the eccentric I l to tilt the plate I2 as desired. The structure so far described, with the exception of the tool holder 9, is well known in the art and particularly in connection with the Brown & Sharpe automatic screw machine. Skiving tools and tool holders heretofore employed, have been designed for the individual work and no tool holder, such as the holder of the present invention, has been employed that will have a wide application and flexible use such as the structure disclosed in this application.

The tool holder 9 embodies a semi-cylindrical head portion I5, having a flat forward face IS. The sides of the head [5 are formed flat and parallel. A concentric drilled and tapped opening I! passes transversely through the head and is chamfered at both ends. The opening I! has threaded engagement with a mounting bolt l8, passing through an opening formed in the wing 8 of the tool post and serving to rigidly clamp the tool holder 9 in frictional contact with the plate l2 after adjustment. The head is further provided with a forwardly extending jaw IQ for the full width of the head and at a right angle to the fiat face [6. The upper surface of the jaw is formed flat and intermediate its width, is provided with an upstanding flat key 20, the upper surface of which is flat and parallel with the upper surface of the jaw. The key extends longitudinally of the jaw and the key and jaw are jointly provided with a vertically arranged square opening 2|, extending entirely therethrough, for the reception of a tool clamping device, to be described.

The tool of the present invention embodies a generally rectangular block of metal 22, having suitable metal cutting characteristics and is of a width corresponding to the width of the jaw [9. The block 22 has a thickness, such that, when mounted upon the upper surface of the jaw l9, its upper fiat face will be substantially in the plane of horizontal movement of the device toward the work either over or under the work. The forward end of the tool 22 is provided with angled cutting edges 23 and 24 and from the cutting edges 23 and 24, the tool is ground rearwardly to provide angled faces 25 and 26. The lower surface of the tool is formed flat for resting engagement upon the jaw l9 and is provided with a T-shaped slot throughout its length. The reduced portion of the slot 21, has a width to snugly receive the key 26, which engagement serves to accurately position the tool upon the jaw I9. A clamping device, comprising a fiat head 28 is adapted to have sliding engagement with the slot 27. The head 28 is provided with a centrally arranged depending stud 29, square in cross section for substantially half its length to engage within the opening 2| of the jaw and serves to prevent rotation of the head. The stud is further formed cylindrical and threaded below the square portion 29, as at 30 and in use projects below the lower side of the jaw, where it is engaged by a preferably hex nut 3 i. Tightening of the nut 3|, serves to clamp the tool 22 firmly to its aligned seat upon the jaw I9, through the medium of the head 28. A slight loosening of the nut 3| permits the tool to be shifted endwise for removal from the holder and the reverse obviously takes place when the tool is replaced. The surface and cuttingconfiguration of the tool will obviously vary in accordance with the particular contour of skiving.

Since in skiving operations, the cutting is done either over or under the work, depending on the direction of turning movement of the work, it becomes necessary to omit the conventional raising block under the tool post when skiving under the work and to employ the raising block under the tool post when skiving over the work on either slide. Thus, the tool holder and its associated tool is raised or lowered below or above the center line of the rotating work stock. As illustrated, the tool holder and tool is mounted upon the forward slide tool post and the raising block has been omitted. The threaded opening I! will obviously permit the holder to be reversed, since it can be clamped from either side.

In the use of the device, the tool is obviously preformed in accordance with the cut to be performed and the diameter of the work. The tool 22 is then mounted upon the jaw by the endwise sliding movement over the key 2%, with the head 23 slidably engaging the slot 2? until the inner end of the tool abuts the fiat wall iii of the tool holder. The nut 3| is then tightened and the tool is rigidly held in cutting position upon the jaw I9 against twisting or shifting. The holder 9 is then positioned upon the wing 8 of the tool post 6 and the clamping bolt 18 engaged with the opening l1. When the holder has been accurately aligned with the work so that the surface of the tool will be absolutely level and will travel in a horizontal plane for cutting engagement with the work, the bolt I8 is tightened and the hook bolt l0 also tightened, at which time the holder and tool are rigidly held in operative position. The purpose in maintaining the tool 22 absolutely level, is to insure against any binding action of the work upon the tool after it performed its cutting action. Further, after cutting has been performed, the slight frictional contact of the surface of the tool with the work will provide a relatively fine finish, in most cases requiring no further polishing to the finished work. Any slight irregular setting of the tool holder may be corrected by an adjustment of the tilt plate I2 through the medium of the eccentric l I. When the tool is to be sharpened, it only becomes necessary to loosen the nut 3i, after which the tool can be easily removed, sharpened and replaced, without disturbing the setting of the tool holder.

It will be apparent from the foregoing, that a very simple and highly efficient and practical tool and tool holder have been designed. The structure is accurate to a fine degree and is applicable to various forms of machines and readily lends itself to skiving in various positions and in a space with respect to the work that has been impracticable heretofore with known skiving tool holders, thus greatly extending the field of use of the device. The structure is cheap to manufacture, durable and conveniently and easily mounted upon a conventional tool post minimum of time and results in a considerable saving of highly expensive skilled labor normally required in arranging and setting the tool prior to its cutting operation.

It is to be understood, that the invention is not limited to the precise arrangement shown, but that it includes within its. purview, whatever changes fairly come within either the spirit or the terms of the appended claims.

Having described my invention, what 1 claim as new and desire to secure by Letters Patent is:

l. A skiving tool and tool holder for detacl able mounting upon the tool posts of automatic screw machines, comprising a tool holder having; a head portion and a forwardly extending jaw. the head portion being drilled and tapped for the reception of a clamping bolt carried by the tool post, the jaw having a fiat tool supporting surface, the tool surface provided with an upstanding key. the jaw and key provided with a squared opening entirely therethrough, a skiving tool for detachable seating engagement upon the tool surface, the tool being slotted for seating engagement over the key, a clamping device having a head for slidable engagement in he slot, a stu: carried by the clamping device for traversing the squared opening, the stud projecting below the jaw and threaded for the reception of a clamping nut, the tool having its upper forward edges angled and ground for cutting engagement with adjacent work.

2. A skiving tool and tool holder for detachable mounting upon that type of automatic screw machines having forward and rear slides that carry tool posts equipped with wing extensions having a tool holder clamping bolt and an eccentrically adjusted tilt plate and clamping hook bolt, the structure that includes a tool holder having a semi-cylindrical head provided with flat parallel side walls and a forwardly extending jaw, the head having a forward flat wall at right angles to the jaw, the head being drilled and tapped on a concentric center transversely for the threaded reception of a clamping bolt carried by the tool post, the drilled and tapped opening being countersunk at opposite ends, the upper surface of the jaw being fiat and horizontally arranged for the seating engagement of the skiving tool, the flat surface of the jaw provided intermediate its width with an integral upstanding key that exends longitudinally of the jaw for the major length thereof, the jaw and key having a square opening formed entirely therethrough vertically, a tool clamping device that includes a clamping head provided with a depending squared stud having its outer portion formed cylindrical and threaded, the threaded portion of the stud projecting below the jaw for threaded reception of a nut, the skiving tool comprising a block having parallel upper and lower walls and a flat inner end wall for parallel engagement with the forward flat wall of the tool holder head, the upper forward edges of the block being ground on opposite angles rearwardly to form cutting edges, the forward end of the block being inclined downwardly and rearwardly from the cutting edges, the block being slotted longitudinally throughout its length in a T-shape with the slot opening upon the bottom surface of the tool for the reception of the key, the head of the tool clamping device adapted to have sliding and clamping engagement within the slot when the tool is shifted to seating engagement with the upper flat surface of the jaw.

3. A skiving tool holder that comprises a semicylindrical head portion having parallel flat side walls and a forward vertical flat wall, the head provided with a forwardly extending lower jaw having a flat upper surface at right angle to the forward fiat wall, the jaw being co-extensive in width with the head, the flat surface of the jaw provided with a longitudinally extending upstanding key intermediate its width, the key and the jaw provided with a vertically arranged square opening entirely there-through, the head provided with a transverse opening entirely therethrough and threaded throughout its length, the opposite ends of the threaded opening being countersunk, the threaded opening being concentric with the head, a skiving tool having forward angled cutting edges and upper and lower flat parallel surfaces and an inner flat wall for abut ting engagement with the fiat wall of the head, the lower flat surface of the tool adapted to have a, parallel seating upon the flat surface of the jaw, the tool being grooved in a T-shape throughout its length with the groove opening upon the lower surface, a clamping device including a flat head that slidably engages the groove when the tool is shifted to a seating engagement with the jaw, the clamping head provided with a square lug that traverses the square opening, the outer end of the lug being formed cylindrical and threaded and of a length to project below the jaw when the tool is in seating position and a clamping nut threaded upon the stud below the aw.

JOHN R. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 867,798 Collins Oct. 8, 1907 1,135,329 Shearer Apr. 13, 1915 1,222,178 Browand Apr. 10, 1917 FOREIGN PATENTS Number Country Date 25,382 Great Britain Nov. 6, 1913 

